The heat shock treament(40℃, 0, 6, 12, 24, 48, 72 and 96 h) was conducted on two non-heading Chinese cabbage varieties, Suzhouqing and Aijiaohuang, which had different heat resistant ability. The activity of leaf protective enzymes, MDA content and membrane permeability were tested in seedling stage. Real-time quantitative PCR(qPCR) was used to detect the expression of BcHsp1 and BcHsp2.The results showed that, after heat shock treament, the activity of protective enzymes in the leaves of heat resistant variety had a higher increase than those in the heat sensitive variety, and the increases of MDA content and electrolyte leakage rate were higher in the heat sensitive variety than those in the heat resistant variety. And the heat-tolerant genes were more stably expressed in heat resistant varitey than those in heat sensitive variety.